The Higgs mechanism: the electroweak symmetry U(1)×SU(2) is spontaneously broken when the scalar field acquires a vacuum expectation value ⟨φ⟩ = v/√2 where v = √(μ²/λ) ≈ 246 GeV. The "Mexican hat" shape gives a ring of degenerate minima. The radial mode becomes the Higgs boson (mH = √(2μ²)), while angular (Goldstone) modes are "eaten" by W±, Z bosons, giving them mass.